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Hibernate 4 Integrator pattern and Spring’s DI

Enabling @Autowired in Hibernate entities.

Create an EventListener that kicks in after a Hibernate LOAD event.  Using AutowireCapableBeanFactory to wire @Autowire’d dependencies.

package be.esus.core.infrastructure.hibernate;

import be.core.architecture.common.locator.SpringLocator;
import org.hibernate.event.spi.PostLoadEvent;
import org.hibernate.event.spi.PostLoadEventListener;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;

// https://jira.spring.io/browse/SPR-9187
public class MyPostLoadEventListener implements PostLoadEventListener {
   @Override
   public void onPostLoad(PostLoadEvent postLoadEvent) {
      Object entity = postLoadEvent.getEntity();

      AutowireCapableBeanFactory spring = SpringLocator.getApplicationContext().getAutowireCapableBeanFactory();
      spring.autowireBean(entity);
   }
}

(SpringLocator is a simple custom class that is ApplicationContextAware in order to have static access to the ApplicationContext)

Register your new listener in Hibernate’s EventListenerRegistry.

package be.esus.core.infrastructure.hibernate;

import org.hibernate.cfg.Configuration;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.event.service.spi.EventListenerRegistry;
import org.hibernate.event.spi.EventType;
import org.hibernate.integrator.spi.Integrator;
import org.hibernate.metamodel.source.MetadataImplementor;
import org.hibernate.service.spi.SessionFactoryServiceRegistry;
import org.springframework.stereotype.Component;

@Component
public class MyEventListenerIntegrator implements Integrator {

   @Override
   public void integrate(Configuration configuration, SessionFactoryImplementor sessionFactory,
                         SessionFactoryServiceRegistry serviceRegistry) {
      EventListenerRegistry eventListenerRegistry = serviceRegistry.getService( EventListenerRegistry.class );

      eventListenerRegistry.appendListeners(EventType.POST_LOAD, new MyPostLoadEventListener());
   }

   @Override
   public void integrate(MetadataImplementor metadataImplementor,
                         SessionFactoryImplementor sessionFactoryImplementor,
                         SessionFactoryServiceRegistry sessionFactoryServiceRegistry) {

   }

   @Override
   public void disintegrate(SessionFactoryImplementor sessionFactoryImplementor,
                            SessionFactoryServiceRegistry sessionFactoryServiceRegistry) {

   }
}

To register your SPI (see service loader), create
a (text) file called org.hibernate.integrator.spi.Integrator in META-INF/services/ and put the FQCN of your integrator in it:

be.esus.core.infrastructure.hibernate.MyEventListenerIntegrator